Automated conveyor cleaning system

ABSTRACT

An automated cleaning system for an endless belt conveyor. The cleaning system having a central control which controls pump supplying hot water, soap and a sanitizer to a plurality of controllable spray valves for plural spray bars.

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application is a Continuation-In-Part of Application Ser.No. 09/501,409, filed on Feb. 10, 2000.

FIELD OF THE INVENTION

[0002] The present invention relates to automated cleaning systems andmore particularly to such a cleaning system for conveyors and conveyorbelts such as those used in food processing plants.

BACKGROUND OF THE INVENTION

[0003] Meat processing and other food packaging plants have a multitudeof conveyor systems that must be cleaned at least nightly in accordancewith government regulations. In the past, workers have brought cartsonto the plant floor with long hoses to clean the conveyors manually.The process consisted of 1) rinsing the conveyors with high-pressure hotwater (˜140° F.@ 250 psi); 2) covering the conveyor with an industrialstrength soap solution; 3) repeating the high-pressure hot water rinseto clear off the soap; 4) lifting the belts out of the conveyors so theaprons surrounding the conveyors and the belt guides underneath can becleaned; 5) repeating the high-pressure hot water rinse to clear off anydebris removed from the aprons or guides; 6) spraying a sanitizingsolution on the conveyor.

[0004] Due to the stringent government regulations, this process isrelatively standard in the food processing industry, although somevariations may exist. The manual process does have several limitations,most obvious of which is amount of labor and time required for theprocess. The labor and time required to clean all of the conveyors in asingle food processing plant will vary greatly depending on the numberand length of the conveyors in the plant, but a typical plant isgenerally cleaned once per day.

SUMMARY OF THE INVENTION

[0005] In accordance with the objects listed above, the presentinvention is an automated conveyor cleaning system that performs most ofthe conventional conveyor cleaning steps without significant userintervention. The system involves outfitting the food processing plantwith centralized high-pressure pumps, a chemical integration platform(“CIP”), and a plurality of strategically placed nozzle spray bars. Thehigh-pressure pump allows for the rinse cycles to be performed atpressures higher than those used with a manual system.

[0006] The steps of the present invention are similar to those outlinedabove for a conventional system. The belts are first subjected to ahigh-pressure hot water rinse sent through the spray bars and nozzles bythe central pumps. The same spray bars and nozzles are then used to coatthe belts with detergent foam, after which the rinsing step is repeated.At this step the automated portion of the system pauses, so that thebelts can be lifted out for cleaning underneath the belts and theconveyor aprons that surround the belts. To further aid the system,special lifters are used with certain types of conveyor belts to liftthe belts out of the conveyor.

[0007] Once the side aprons are cleaned and the belts are returned totheir operating location, the automated process continues with ahigh-pressure rerinsing to remove any debris left during the cleaning ofthe aprons or other manual cleaning. The spray bars then coat the beltwith a low-pressure spray of sanitizing solution, which is allowed todry in place. Preferably the spray bars are then purged with pressurizedair to remove any excess sanitizer in the spray bars.

[0008] Programmable logic controllers (“PLCs”) are used with the CIP,with the inlet valves of the spray bars, and with the high-pressurepumps. The conveyors (that have some common properties) are groupedtogether and each such group is controlled by a PLC. For each plantthere could be many such groups called zones. The PLCs are allnetworked, possibly by a proprietary fiber optic system or wirelessEthernet and are in turn networked with a supervisory control system(typically run on an NT PC). This allows for logging of the variousparameters used for cleaning (i.e. temperatures, pressure, time) and theamount of water or chemicals used.

[0009] The system can also easily change the dilution rate for thechemicals (stored in bulk) at the CIP. The CIP will typically have threebulk chemicals connected thereto: an industrial soap, and two types ofsanitizers (the sanitizers are alternated based on the bacteria type andits resistance to the sanitizer), and is capable of supplying thediluted chemicals to the entire plant. The operation of thehigh-pressure pumps is preferably driven, by variable frequency drives(“VFD”) and controlled by one of the PLCs mentioned above.

BRIEF DESCRIPTION OF DRAWINGS

[0010] So that the manner in which the above-identified features,advantages, and objects of the present invention are attained and can beunderstood in detail, a more particular description of the invention,briefly summarized above, may be had by reference to the embodimentthereof which is illustrated in the appended drawings.

[0011] It is noted, however, that the appended drawings illustrate onlya typical embodiment of this invention and is therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments. Reference the appended drawings, wherein:

[0012]FIG. 1 is a schematic view of the central facilities used in thepresent invention;

[0013]FIG. 2 is an isometric view of a typical manifold station used inthe present invention;

[0014]FIG. 3 is a front view of a spray bar used in the presentinvention, showing its relation to a conveyor belt;

[0015]FIG. 4 is an isometric view of the spray bar shown in FIG. 3;

[0016]FIG. 5 is a side view of an alternate spray bar used in thepresent invention, showing its relation to a conveyor belt;

[0017]FIG. 6 is a front view of the spray bar shown in FIG. 5;

[0018]FIG. 7 is a close-up side view of nozzles on a secondary spray barfor use with cleated conveyor belts in the present invention;

[0019]FIG. 8 is an isometric view of belt lifters in a resting state foruse with the present invention;

[0020]FIG. 9 is an isometric view of the belt lifters shown in FIG. 8 inan extended state;

[0021]FIG. 10 is an isometric view of the belt lifters shown in FIG. 9in operation in relation to a conveyor system;

[0022]FIG. 11 is a system block diagram showing the SCADA and itsconnection to the system PLCs;

[0023]FIG. 12 is a conveyor belt cleaning spray bar with a center cleatcleaning spray bar;

[0024]FIG. 12a is a sectional view of a conveyor belt cleaning spray barwith a center cleat cleaning spray bar;

[0025]FIG. 12b is an illustration of a conveyor belt cleaning spray barand center cleat cleaning spray bar nozzle configuration;

[0026]FIG. 13 is a front view of a belt constraint;

[0027]FIG. 13a is a top view of a belt constraint; and

[0028]FIG. 14 is an illustration of a system having a throttling valve.

DETAILED DESCRIPTION OF THE INVENTION

[0029] Referring now to FIG. 1 the central facilities 10 of the presentsystem are shown in schematic form. The central facilities 10 supply thenecessary resources to an entire food processing plant for the presentsystem to function, although it is conceivable to maintain a second orsubsequent set of central facilities either as a redundant backup systemor to divide the plant into two sections, each set of central facilitiesmaintaining one section. It is preferable, however, to maintain only asingle set of central facilities 10 to retain simplicity, as the centralfacilities 10 can be expanded to increase capacity plant-wide.

[0030] The central facilities 10 comprise sources for each of theresources used by the system. Namely, there exists a hot water source12, a compressed air source 14, and a plurality of bulk chemical sources16, 18, 20. It is possible to keep the resource sources in a differentphysical location from the remainder of the central facilities 10,although it is preferable to keep the bulk chemical sources 16, 18, 20nearby.

[0031] As described below, the typical bulk chemicals in the preferredembodiment will comprise an industrial strength detergent 16, and twosanitizers—one acidic 18 and one basic 20. However, various othersanitizers can be utilized such as bleach, alcohol, or ammonia basedsanitizers. The bulk chemical sources are in communication with achemical integration platform (“CIP”) 22. The CIP 22 comprises aconglomeration of pumps, a programmable logic controller (“PLC”) 23,instrumentation (i.e. sensors and meters), and starters locatedtypically on a single skid. The CIP 22 obtains concentrated chemicalfrom the bulk sources 16, 18, 20, possibly with the aid of transferpumps 24. It also receives water from a cool water source 26 to dilutewith the concentrated chemical and keeps an ample supply of eachchemical prediluted in batch tanks 28. The PLC 23 monitors the level ofdiluted chemical in the batch tanks 28 and dilutes more as needed. TheCIP 22 also contains the pumps to pump the diluted chemical from thebatch tanks 28 to the remainder of the plant through the output lines30, 32, 34. In the prior art manual cleaning method, these chemicalswould have to be manually prediluted and transported in the batch tanksto the various conveyor systems.

[0032] In addition to the software interlock that ensures that only onechemical distribution pump is in operation, the electrical wiring ishard wired such that only one pump can be energized at any given time.In normal operation, this method will eliminate the possibility of morethan one chemical being supplied and the danger of the reaction ofmixing two incompatible chemicals.

[0033] Also located in the central facilities 10 are high-pressure pumps36 for the hot water supply 12. Space may be reserved in the centralfacilities for additional pumps, in the event, for example, that plantcapacity is expanded. In a similar manner, the types and quantities ofchemicals may also be expanded. FIG. 1 shows an example of centralfacilities 10 having two pumps 36 and space reserved 38 for oneadditional pump 36 in the event of future expansion. Like the CIP 22,the hot water pumps 36 will have a PLC 37 attached thereto controllingthe pumps' operation. The water in the hot water supply 12 shouldpreferably be between 100° F. and 180° F. and the pumps 36 shouldpreferably maintain the plant's supply of hot water at at least 300 psi.Current governmental regulations require water temperature of less than180° F. for safety reasons. Applicants have found that 140° F. isoptimal, given current regulations. However, should regulations change,hotter water temperatures would be preferable and are within the scopeof the present invention. Applicants have also found that 500 psi waterpressure is optimal for the present invention, however, higher pressuresmay be used. The pumps 36 supply hot water to the plant through theoutput line 40, and should preferably use variable frequency drives(“VFD”). The centralized pumps 36 allow for significantly higherpressure water to be used than what is safely obtainable using a manualcleaning system. Furthermore, it is conceivable to have the pumps 36pump cold water for rinsing during some stages of the cleaning processto save money and reduce condensation in the plant.

[0034] The compressed air is directed from its supply 14 straight to theoutput line 42, and on to the remainder of the plant. A portion of thisair, however, may possibly be diverted to the CIP 22 for its use and toa separate output line 44 for instrumentation use.

[0035] Referring now to FIG. 2, a typical manifold station 46 for thepreferred system is shown. A plurality of these manifold stations 46 aredispersed throughout the plant. The manifold station 46 taps each of thesupply lines 48, which run throughout the plant. There are typically sixsupply lines 48, one for each output line (30, 32, 34, 40, 42, 44)located at the central facilities. Each manifold station 46 willtypically have four valves one for the hot water supply 50, and one foreach of the three diluted chemical types 52, 54, 56. The manifoldstation 46 should preferably have a single manifold drain 58.Additionally, each manifold station will have backflow prevention (notshown) to protect the potable water supply. Such backflow prevention iswell-known in the art. Each manifold station 46 is controlled by anearby PLC 47, although multiple manifold stations 46 may be controlledby a single PLC 47. In the preferred embodiment the plant is dividedinto a few separate zones, each manifold station belonging to exactlyone zone, and each zone having exactly one PLC 47. This arrangementallows for the conveyors in one section of the plant to be cleaned whilethe remainder of the plant stays operational.

[0036] From the main high-pressure water loop, as an option, the systemcould provide many branches with a pressure-reducing valve for hosedrops to allow manual washing. From the main chemical loop that iscarrying diluted chemicals, as an option, the system could also providediluted chemical hose drops that provide diluted chemical for manualchemical spray. This eliminates workers handling of the chemicals andalso insures proper chemical concentration. These hose drops and dilutedchemical drops can optionally be located at the manifold stationdepicted in FIG. 2 and connected thereto or the hose drop and dilutedchemical drop can be branches from the main loop of the fluidcommunication system.

[0037] The PLC's 47 used to control the manifold stations 46, as well asthe PLC 37 for the hot water pumps 36 and the PLC 23 for the CIP 22 canbe any off-the-shelf type of PLC that is readily available. Theinventors have found that the Momentum™ available from the Modicon®Corporation of Andover, Mass. is particularly suitable for the presentinvention. The PLC's are all interconnected and in communication with asupervisory control and data acquisition (SCADA) unit 94. The connectionbetween the PLC's and the SCADA 94 may be made by any conventionalnetworking architecture, such as Modbus, Ethernet, or DeviceNet or anysimilar proprietary architecture. Each PLC preferably also has anoperator panel 96 connected thereto. FIG. 11 shows a typical systemblock diagram of the interconnection of the SCADA 94, the PLCs, and theoperator panels 96, connected with a ring network 98.

[0038] The SCADA 94 can take the form of a simple controller with inputmechanisms as simple as a touch keypad. The preferred embodiment of theSCADA 94 is, however, a computer workstation, such as one based on anIntel® architecture running Microsoft® Windows® NT/2000 and SCADAsoftware, such as that available from Intellution, Inc. of Norwood,Mass. The PLC's are programmed with logic controller software, such asProWorx NxT® available from Taylor Industrial Software of Edmonton, AB.The SCADA is responsible for sending control signals to the various PLCsas is described in further detail below. In case of a SCADA failure, thesystem may be operated directly from each PLC individually, for exampleby use of an operator panel 96.

[0039] Connected to each manifold station 46 is a plurality of spraybars 60, 60 a. A typical spray bar 60 can be shown in FIGS. 3 and 4, oran alternative embodiment 60 a is shown in FIGS. 5 and 6. The preferredspray bar 60, 60 a will have an upper 62, 62 a and lower leg 64, 64 a,each leg having a plurality of nozzles 66. The spray bars 60, 60 a arepreferably mounted to the underside of a conveyor system such that thelegs straddle the conveyor belt 68 as it moves in the inverted orunderside position (that is the carrying surface of the belt 68 is faceddown). This allows the spray bars 60, 60 a to be permanently mountedwithout obstructing flow of product on the belt 68. Each conveyor belt68 will have at least one spray bar 60, 60 a. Certain beltconfigurations, such as those with cleats 70, will have an additionalspray bar 72 designed specifically to clean the cleats 70. An example ofsuch a configuration is shown in FIG. 7. As can also be seen in FIG. 7,a guide 69 may be used to constrain the conveyor belt 68 duringspraying.

[0040] The spray bar can optionally be strategically located at theidler end of the conveyor (closer to the pulley) so that the water issprayed while the hinges are opening on the hinged (Intralox) typeconveyors. It also helps in chemical retention after the solution issprayed on the belts. The chemical will stay on top of the belt.

[0041] As discussed above, two different spray bars for cleaning thebelt and cleats can be utilized. The same effect can be achieved byintegrating the regular (flat belt) upper spray bar with a center cleatspray bar. The resultant is a new spray with nozzles at different anglesto clean the flat belt and also the cleats. This reduces the waterconsumption.

[0042] Referring to FIGS. 12, 12a and 12 b, the upper leg portion 102 ofthe spray bar has a single row of nozzles 103 designed with an angle 105cutting against the direction of conveyance 113 optimal for cleaning thebelt 101. The center leg portion of the spray bar 104 has two rows ofnozzles 107 optimally angled with angle 109 to clean the cleats 111.FIG. 12b is provided only as an illustration of the nozzle arrangement.The lower leg portion of the spray bar 106 has a single row of nozzles115 similar to that of the upper leg portion 102 and has an angle 117cutting against the direction of conveyance 113 and optimal for cleaningthe belt 101.

[0043] The nozzles 66 of the lower leg 64, 64 a of the spray bar 60, 60a are preferably angled against the direction of movement of the belt 68to create a cutting effect with the hot water, however such angling isnot required to practice the invention. If an angle is used, it will beslight, but the optimal angle will vary with the conveyor configuration.For example, a flattop belt may use an angle of about approximately 15°and a typical angle for a cleated belt may be in the vicinity of 35°(from vertical). FIG. 7 shows the nozzles 66 configured to clean thecleats 70 on the belts 68 so equipped. The angles of the nozzles 66 forcleaning the cleats 70 are typically greater than the main lower nozzles66, but the angle will vary depending on the size of the cleat. When thesecondary spray bars 72 are used for cleated belts, they shouldpreferably be located near (between 2 and 3 feet) the primary spray bar60, 60 a.

[0044]FIGS. 3 and 4 show one embodiment of the spray bar 60. In thisembodiment a flexible hose 74 pending from the manifold station 46delivers whatever resource is provided there. The hose 74 leads into a“T” connector 76, which simultaneously supplies the upper and lower legs62, 64 of the spray bar 60. The upper leg 62 of the spray bar 60 ispassed through retainers 78 connected to the conveyor, one proximate tothe “T” connector 76 and one distal thereto.

[0045] An alternate spray bar 60 a is shown in FIGS. 5 and 6. In thisembodiment both legs 62 a, 64 a of the spray bar 60 a are connected by ahard pipe 65 to the inlet 67 of the spray bar 60 a. This provides a moredurable connection than the embodiment shown in FIGS. 3 and 4. As canalso be seen in FIG. 6, both the lower and upper legs 62 a, 64 a of thespray bar 60 a are retained by the conveyor 80, both proximate anddistal to the spray bar inlet 67. It can also be seen from FIG. 5 thatthe lower leg 62 a of the spray bar 60 a is offset downstream (inrelation to the belt travel) from the upper leg 64 a. This allows thenozzles 66 on the upper leg 62 a to be aimed straight downward and thenozzles 66 on the lower leg 64 a to be angled as previously discussed,and still contact the belt 68 at the same point but on opposingsurfaces.

[0046] With most conveyors there will also be a belt lifting apparatus82 displayed in FIGS. 8-10. The belt lifting apparatus 82 is used in themajority of conveyors 80 except those without sufficient slack to belifted, such as metal belts. FIG. 8 shows the belt lifters 82 in theresting (or contracting) state, which is used during normal operationand during the automated phases of the cleaning cycle. The belt lifter82 comprises a pair of axles 84, 86, a pair of pivot arms 88 that rotateabout one axle 84, a pair of extenders 90 that rotate about the otheraxle 86, and a pair of rollers 92 located at the end of the pivot arms88 respectively. The extenders 90 are coupled respectively to the pivotarms 88, and are preferably pneumatically controlled, although ahydraulic, electrical or manual arrangement would also be feasible. Themanual belt lifting device can have a crank handle for extending andretracting the lifters. Depending on belt width, the belt lifter 82 maycomprise only a single pivot arm 88, extender 90, and roller 92 (fornarrow belts) or more than two pivot arms 88, extenders 90, and rollers92 (for wider belts). For safety reasons, it is desirable to have theactuation of the extenders 90, and thereby the belt lifters 82, spreadover several seconds.

[0047] For the more narrow belts (for example, less that approximately12′ wide), the belt may have only a single lifter to raise the belts.With only a single lifter, the belt has a tendency to fall off thelifter arm roller when lifted. The lifter mechanism can be designed andbuilt with a constraint device that restricts the movement of the beltwhen it is lifted up and prevents it from falling off. FIGS. 13 and 13ashow a front view and a top view, respectively, of one embodiment of abelt constraint 122 for single arm lifters 123. The belt constraint isattached to the conveyor support structure 124. The legs 126 of theconstraint straddle the conveyor belt 128 on either side and extendupward above the belt and are canted inwardly toward one another bottomto top, when the single belt lifter lifts the narrow belt 128, the beltconstraint 122 prevents the belt from falling off the lifter. The beltconstraint can take on other embodiments that have constraint members orlegs that extend upward on either side of the belt.

[0048] During the manual cleaning phase of the present system (describedin more detail below) the extenders 90 are extended from theircontracted resting state. This extended state is shown in FIG. 9. Theextenders 90 are noticeably closer in length to the pivot arms 88 whenin the extended state than when in the resting state. Each belt 68 onwhich belt lifters 82 are used will have more than one belt lifter 82.An example belt 68 with the belt lifters 82 in the extended state isshown in FIG. 10. As readily seen from the drawings, the slack of thebelt 68 is taken up by the rollers 92 and the apron of the conveyor 80,as well as other components normally hidden under the belt 68, areexposed for manual cleaning.

[0049] For safety reasons, it is not recommended to have the extenders90 activated by the SCADA unit 94, but this arrangement is possible. Inthe preferred embodiment, the control for pneumatically activating theextenders is located in each zone at the operator panel 96.

[0050] The entire system has two modes of operation—sequential andautomated. In a typical automated mode, an operator located at the SCADAunit 94 indicates which zones are to be cleaned. The SCADA 94 sends asignal to the PLC 37 for the hot water pumps 36 to start. Once the pumpsare started, the SCADA 94 sends a signal to the PLC 47 for the manifoldstations 46 in the zone(s) to be cleaned to commence the initial phases.The initial phases consist of rinsing the belt 68 with the high-pressurehot water, covering the belt 68 with foam from a low pressure spray ofthe industrial detergent 16, and repeating the high-pressure rinsingphase to remove the foam. The PLC 47 for a zone to be cleaned receivesthose signals and opens the valves 50 for the hot water forpredetermined length of time, then closes the hot water valves 60 andopens the detergent valves 52. After another predetermined length oftime, the PLC 47 closes the detergent valves 52 and reopens the hotwater valves 50. Applicants recommend that the belts undergo between oneand four revolutions of the belt 68 during each spray cycle. The PLC 47may also open the valves in its zone sequentially so that only a portionof its spray bars 60 are active at any given time.

[0051] Once the initial phases are completed in the automated mode, itis preferable for the operator to lock out the conveyors, so that theconveyor belts 68 in the zones being cleaned will not run, but it ispossible to operate the belt lifters 82 while the belts 68 are running.For belts 68 equipped with belt lifters 82, the belt lifters 82 areactivated lifting the slack in the belts 68 out of the conveyor 80.Certain types of belts 68, such as those made of metal, withoutsufficient slack, are left in place. Cleaning personnel then useconventional cleaning methods to manually clean components of theconveyor 80 other than the belt 68. This includes the conveyor apron andthe components under the belt 68 normally hidden from sight. This methodof lifting the belts 68 is unquestionably safer and quicker than theprior art method of using crowbars to pry the belts out of the conveyorsystem. In the case of belts 68 without sufficient slack for beltlifters, manually cleaning of the aprons is done with the belts inplace.

[0052] Once the manual cleaning phase is completed, the belt lifters 82are returned to their resting state and, if the belts 68 are locked, theoperator unlocks them. The operator indicates at the SCADA 94 that thefinal phases are to commence. The final phases consist of again rinsingthe belts 68 to remove any debris loosened during the manual phase and asanitizing phase. The rinsing phase is carried out identically to theprevious rinsing phases, whereby the zone PLC 47 opens the hot watervalves 50 at the manifold stations 46, either in unison or sequentially.The PLC 47 then closes the hot water valves 50 and opens the appropriatesanitizing valves 54, 56. The SCADA 94 will signal the PLCs 23, 47 whichsanitizer is to be used. The preferred embodiment is a system having twosanitizer types although more or fewer may be used. When two are usedone may be acidic 18 and the other may be basic 20. However, asdiscussed above, other sanitizers, such as bleach, can be utilized. Thisrotation of sanitizer type is intended to prevent the formation ofresistant strains of bacteria that adapt to one type of sanitizer, andis well-known in the art. Optimally, a final step may be included,whereby after PLC 47 closes the sanitizer valve 54, 56, it opensmanifold drain 58 for a period of time to release any fluids trapped inthe manifold station 46. The PLC 47 would then close the manifold drain58 and purge the spray bars 60, 60 a with air from the compressed airsource 14. The purging prevents clogging of the nozzles 66 and preventssanitizer from dripping on the belts 68 during operation.

[0053] The final step of purging the Intellijanitor system can beaccomplished by purging all lines (downstream of valves) with air toremove any remnant liquid. The following day or the next time theIntellijanitor system is started, there is a likelihood of getting waterhammer (on high-pressure rinse) because of empty water lines. Therefore,performance of a pre-fill procedure allows the water at house-pressure(say 70-psi) to fill all pipes, thereby providing some back-pressurewhile running the high-pressure rinse step. In addition to the pre-fillprocedure, a control valve is used and this valve is designed as athrottling valve to take abuse of high-low pressure swings in theoperation of the cleanup system. Use of a throttling valve eliminatesthe need to utilize more expensive valves at the manifold that aredesigned to withstand the pressure swings and water hammer. Use of thethrottling valve design allows the system to also be utilized withvarious line sizes because the throttling valve allows the system towithstand sudden pressure swing or water hammer.

[0054] For example, assume there are five (5) downstream valves that areconnected to different spray bars. The control valve or throttling valveis upstream of this bank of five (5) downstream valves 132. During thehigh-pressure rinse, the PLC sends a signal to open the first valve inthe bank while the control valve or throttling valve 134 is still closedand holding, for example, 500-psi pressure. Once the first valve isopened, then the control valve 134 slowly opens up. Please note thateach downstream valve can be opened for a preset time. A few secondsbefore the closing cycle of the first valve, the control valve 134throttles down to substantially close, for example, about approximately80% closed. This reduces the flow and pressure of the fluid. Now thesecond valve in the bank 132 opens up and the first valve in the bank ofvalves is closed. After the second valve is completely open, then thecontrol valve opens up from, for example, 20% open to, for example, 100%open. The same cycle continues for the rest of the valves in the bank132. For the final fifth downstream valve, the control valve is closedfirst and then the fifth valve closes. This rinse cycle can be repeatedfor a single downstream valve and its respective spray bar repetitivelyfor each rinse cycle or can be sequentially cycled through a bank ofdownstream valves as described above or any multiple combinations andvariations thereof. Please note the number of banks or valves in a bankmay vary to more than five (5) or less than five (5). The pressures andthe open and closed percentages may vary depending on the dynamics ofthe given system. The amount or percent of opening and closing of thethrottling valve may vary depending on the given system. Also, a singledownstream valve can be communicably connected to and control multiplespray bars.

[0055] Referring to FIG. 14, for illustration of one embodiment, threechemical input lines 136, one air line 138 and one high-pressure centerline 140 is shown. The three chemical lines and the high-pressure waterlines can each have a regulating throttling valve or control valve 134,or optimally, one control valve can be positioned just downstream of thejunction 142 of the four lines for throttling control of all four lines.

[0056] The chemicals are preferably sprayed at a low pressure thatideally ranges from 5 to 100 psi. Applicants have found thatapproximately 15 psi is optimal for the low-pressure sprays. Thus, forthis low pressure, depending on the system and line sizes a throttlingvalve may not be required.

[0057] The entire time to complete cleaning in the automated mode ishalf that of the conventional, prior art method. This time savingsallows a cleaning to be done in the middle of the day, between shiftsfor instance. Furthermore, this invention allows a sanitizer (perhaps athird type thereof) to be continuously sprayed on the belts duringnormal operation. Additionally, because the present system requires onlya minimum of one revolution of each belt per cycle, as compared to fivein the prior art method, the present system uses significantly lesswater and chemical than the conventional method, even though the spraybars 60, 60 a may have a significantly higher water consumption ratethan the hoses used in the prior art manual method. Actual waterconsumption can of course be calculated by multiplying the consumptionrate per belt revolution by the number of revolutions.

[0058] In the alternative sequential mode, the operator instructs theSCADA 94 to commence each phase individually (i.e., rinsing, covering,sanitizing). After each individual phase is completed the system pausesuntil the operator indicates that he or she wishes to proceed.

[0059] It is preferable following the sanitizing phase to purge thenozzles and spray bars of any remaining liquid. This is accomplished atthe direction of the SCADA 94 by the zone PLC's 47 using the compressedair supply for the plant.

[0060] The present invention is suitable for retrofit on a wide varietyof conveyor systems. In particular, the present system seems well suitedfor the 100, 200, 300, 400, 800, 900, 1800, 2000, and 2200 seriesIntralox® acetal conveyor belts (flattop, nub top, and cleated) from theLaitram Corporation of New Orleans, La. It will also work with Volda andDiamond Back PVC conveyor belts, as well as polymer or steel slatconveyor belts and many other varieties. It is also possible to factoryinstall components for the present system in the conveyor system.

[0061] In practice, a quality control inspection is then performed toinsure that remaining level of bacteria on the conveyor equipment iswithin safe levels typically regulated by the government. If thebacteria levels exceed safe levels, the entire cleaning process must berepeated for that conveyor. Initial testing has shown that the presentsystem requires recleaning 40% less often than the conventional, priorart method.

[0062] Optionally, the present system allows for logging of certaininformation that the prior art method cannot easily accommodate. Forinstance, the SCADA 94 can keep a log of how much water is consumed inthe process, as well as quantities for each of the chemicals, and otheroperating parameters. Furthermore, for inspectors' use, it can recordthe water temperature for each cleaning cycle and the type of sanitizerthat was used on a given day, etc.

[0063] The SCADA unit controls and monitors all the Zone PLC, pump PLC,Chemical Distribution System, records and displays pressure, flow andtemperature of the water or chemical that is being used. It displays thereal time status of all instrumentation and also shows the status of thecleaning operation. For example, it can display which valve is open andthe group of belts being washed. Maintenance personnel can identify anypossible failures in the system. It can also act as a powerful dataacquisition tool. Quality Control can analyze the graphs for any givenday and time for the amount of water or chemical being used, pressureand temperature of the water or chemical being used. The data gatheredby SCADA can be utilized in analyzing the effectiveness of the cleaningcycles, the cleaning fluids and chemicals, and water temperatures andpressures. If contaminants are detected, the cleaning operation data canbe reviewed and analyzed.

[0064] As an alternative embodiment to the conveyor cleaning system asdescribed above, the spray bars can be appropriately mounted to theconveyor structure while having no fluid connection to the manifoldstation or the main loop. The stand-alone spray bar can be adapted witha hose connection such that a fluid source base can be manuallyconnected thereto, and thereby manually providing a source of fluid.This alternative embodiment can be useful for existing facilities wheremodification of the facility infrastructure is not a viable option.

[0065] While the foregoing is directed to the preferred embodiments ofthe present invention, other and further embodiments of the inventionmay be devised without departing from the basic scope thereof, and thescope thereof is determined by the claims, which follow.

We claim:
 1. A method of cleaning a conveyor, comprising the steps of:a. providing a control unit operatively linked to at least one fluidsupply where said at least one control unit further operatively linkedto at least one spray bar in fluid communication with said fluid supplyand having a plurality of nozzles directed toward at least one side ofthe conveyor belt for controlling said fluid supply and said spray bar;b. rinsing a conveyor belt with the spray bar using fluid from the atleast one fluid supply responsive to an operator input at the controlunit; c. purging with a compressed air source the at least one spray barand nozzles and all fluid communication lines between the at least onefluid supply and the at least one spray bar; and d. prefilling the fluidcommunication lines prior to starting a next cleaning cycle with waterat house pressure providing back-pressure for the next cleaning cycle.2. The method of cleaning a conveyor as recited in claim 1 furthercomprising the steps of: a. monitoring and recording operational datarelating to fluid distribution, fluid pressure, fluid temperature andrinse cycle; and b. retrieving said operational data for analyzingcleaning effectiveness.
 3. A method of cleaning a conveyor, comprisingthe steps of: a. providing a control unit operatively linked to at leastone fluid supply, a throttling valve, and a first downstream valveoperatively connected to at least one spray bar for controlling said atleast one spray bar where said at least one spray bar is in fluidcommunication with said at least one fluid supply through saidthrottling valve and said first downstream valve; b. opening the firstdown stream valve; c. opening the throttling valve; d. rinsing aconveyor belt with the at least one spray bar using fluid from the atleast one fluid supply responsive to operator input at the control unit;e. closing the throttling valve; f. closing the first downstream valve;and g. repeating steps b through f for each rinsing cycle.
 4. A methodof cleaning a conveyor, comprising the steps of: a. providing a controlunit operatively linked to at least one fluid supply, a throttlingvalve, and a plurality of downstream valves operatively connected to aplurality of spray bars for controlling said fluid supply and saidplurality of spray bars where said plurality of spray bars are in fluidcommunication with said at least one fluid supply through saidthrottling valve and said plurality of downstream valves; b. opening afirst of said plurality of downstream valves; c. opening the throttlingvalve; d. rinsing a first conveyor belt with a first of a plurality ofspray bars using fluid from the at least one fluid supply responsive toan operator input at the control unit; e. substantially closing thethrottling valve; f. closing the first of said plurality of downstreamvalves; g. repeating steps b through f for each of the remainingdownstream valves of the plurality of downstream valves for each rinsecycle of the respective spray bars; and h. closing the throttling valve.5. An automated cleaning system for a conveyor having a belt comprising:a central control unit; a chemical integration platform operativelylinked to and controlled by said control unit where said chemicalintegration platform is operable to receive at least one bulk chemical,and dilute and store the diluted at least one bulk chemical; saidchemical integration platform having a software and hardware interlockoperable to prevent more than one chemical being supplied at the sametime to prevent incompatible chemical mixing; at least one manifoldstation in fluid communication with said chemical integration platformwhere said manifold station is operable to control fluid flow from thechemical integration platform to at least one spray bar in fluidcommunication therewith; and at least one programmable logic controlleroperatively coupled to said chemical integration platform and saidmanifold station for controlling said manifold station and said chemicalintegration platform operations and said programmable logic controllerfurther operatively coupled to said control unit.
 6. The automatedcleaning system for a conveyor belt as recited in claim 5 where saidconveyor further comprises: a belt constraint having constraint membersmounted to extend vertically upward on both sides of the belt forpreventing the belt from falling off a belt lifter.
 7. The automatedcleaning system for a conveyor belt as recited in claim 5 furthercomprising: at least one hose drop for manual washing where said atleast one hose drop is in fluid communication with a main loop of theautomated cleaning system.
 8. The automated cleaning system for aconveyor belt as recited in claim 5 further comprising: at least onediluted chemical drop for manual chemical spray where said at least onechemical drop is in fluid communication with said chemical integrationplatform.
 9. The automated cleaning system for a conveyor belt asrecited in claim 5 further comprising: a conveyor; and where said spraybar further comprises: an inlet line in fluid communication with saidmanifold station; an upper and lower leg portion communicably linked tosaid inlet line; where said inlet line is operable to channel fluid tosaid upper and lower leg portion; and where said upper and lowerportions straddle said conveyor belt as it moves along its undersideposition and disposed proximate an idler end of the conveyor.
 10. Theautomated cleaning system for a conveyor belt as recited in claim 9where said spray bar further comprises a center leg portion having atleast one nozzle optimally angled for cleat cleaning and where saidinlet is further operable to channel fluid to the center leg portion andwhere the upper and center leg portions straddle the conveyor belt. 11.The automated cleaning system for a conveyor belt as recited in claim 5where said manifold station is in fluid communication with ahigh-pressure fluid supply through a throttling valve controllablylinked to said control unit and where the fluid communication betweenthe spray bar and the manifold station is through a downstream valve.